Schoeps UNIVERSAL-OMNI-H-ST, UNIVERSAL-OMNI-S-ST, WIDE-CARDIOID-ST, SWITCHABLE-PATTRN-ST, SUPERCARDIOID-ST Users Manual

MK --

Microphone Capsules

CMC --

Microphone Amplifiers

User Guide

Colette
Modular System

Colette
Modular System

Table of Contents

page
System Overview 2
CMC -- Microphone Amplifiers 3

Phantom Powering 5
Technical Specifications 7
Notes on Electromagnetic Compatibility 7
Block Diagram 8

MK -- Microphone Capsules 9

Capsule Selection 9
Attaching a Capsule 9
Basic Characteristics of Transducers 10
Suggested Capsules for Specific Applications 11
Pressure Transducers 12
Boundary Layer Microphones 13

Pressure Gradient Transducers 14
Specifications for Complete Microphones 21
Care and Maintenance 22
Possible Problems 22
Warranty 24

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

System Overview (Extract)

Colette Modular System

2

inline filters

inline

attenuator

microphone

capsules

attenuator

swivel

low-cut

filter

microphone

amplifiers

.
.
.

20 capsules
in all

RC KC

Active Tube

(special
version)

MK DZC GVC

KC

Active Cable

CUT

Signal:

balanced
unbalanced

TR 200 KCg Active
Table Stand

RC

Active Tube

LP 40 U

low-pass filter

Active Accessories

CMC 6, P12 / P48

CMC 3, P12

CMC 5, P48

LC 60, LC 120

low-cut filters

OSIX CI

elastic suspension
with Active Cable

e.g. VMS 5 U

microphone preamplifier
with M/S matrix

MDZ 10,
MDZ 20

CMC 4, T12

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

CMC -- Microphone Amplifiers

Microphone Amplifiers

3

Dear customer:

Thank you for choosing SCHOEPS CMC
(”Colette”) Series microphones. This is the most
extensive and diverse modular microphone
system in the world, offering the highest pos­sible professional sound quality in an extremely
wide range of practical configurations. A system
overview is shown on page 2.

Colette Modular System

A condenser microphone is formed by the
combination of two main components: a cap­sule and a microphone amplifier:

The capsule is the component which converts
sound waves into a varying electrical voltage.
It determines the directionality and, for the
most part, the sound quality of the microphone.
The amplifier is the other main component,
with the circuitry needed to accept external
powering, polarize (charge) the capacitive
capsule, obtain the audio signal from it, and
convert that signal to one which is balanced
and low-impedance.

Microphones of the Colette Series are mod­ular: Any type of CMC microphone amplifier
can be used with any type of Colette capsule.
Approximately 20 different capsule types (MK --)
are available for wide-ranging applications,
and several types of amplifier (CMC --) are
available for various powering and connection
schemes.

In addition, the practical value of a Colette
Series microphone is greatly enhanced by
Colette ”Active Accessories” – special goose­necks, ultra-thin cables or narrow extension
tubes which allow the capsule to be separated
some distance from its amplifier and placed
unobtrusively, as if it were a miniature micro­phone. Colette Active Cables are often used
to help conceal microphones for film and video
production, while Colette Active Extension
Tubes have become a mainstay of concert

amplification, recording and broadcasting.
The active circuitry in these accessories converts
the audio signal to lower impedance directly
at the capsule, so that there is no loss of sound
quality:

In the following pages you will find technical
information, application hints and advice con­cerning the care and maintenance of these
microphones. We begin by considering the
CMC amplifier and how to power and connect
SCHOEPS condenser microphones; the second
part of this manual concerns the capsules of
the Colette Series. For information on acces­sories (including Active Accessories), please see
our main catalog or visit www.schoeps.de.

CMC -- Microphone Amplifiers

...are distinguished by:
– flat frequency response
– low noise and distortion
– balanced, symmetrical, very low-impedance

output

– ability to be used with very long cables

(e.g. several hundred meters)

– versions for various powering schemes

Several standard versions are available. All
feature a symmetrical, class-A output stage
which uses neither coupling conden sers nor an
output transformer. This leads to a low output
impedance, insensitivity to electrical interfer­ence, low distortion and light weight.

CMC amplifiers are electrically active com ­po nents which require operating current. This
will most often be supplied by the inputs of a
mixer, preamplifier (such as the SCHOEPS
VMS 5U shown on page 2) or recorder that
has suitable microphone powering built in.
Otherwise, a stand-alone microphone power
supply of proper type can be used.

Standard Versions

Four standard models of CMC amplifier are
offered to fit the specific type(s) of microphone

MK-- CMC--

+

++

Active Accessories

powering which the user expects to encounter.
Variants of these types are also available, offer­ing different output levels and/or extended
frequency range. Each amplifier works only with
the specific type and voltage(s) of power ing
for which it is designed.

Please note: The two amplifiers in a stereo pair

of CMC microphones should be of the same
type. For critical applications, pairs of capsules
can be selected at the factory for pre cisely
matched sensitivity and frequency response.
(A small extra fee is charged for this service.)

Most modern, solid-state professional micro ­phones use a standardized powering scheme
known as ”phantom powering,” and most
recording equipment offers a 48-Volt supply
for such microphones. Some equipment, how­ever, provides a 12-Volt supply for phantom
powering, or can be readily modified to provide
such a supply. The SCHOEPS CMC 6 amplifier
series can work with either voltage, switching
its circuitry automatically to the corresponding
mode of operation. It maintains the same level
of performance in either mode, while drawing
only the necessary amount of current from the
phantom supply.

Note that the CMC 6 is designed to work
with standard 12-Volt or standard 48-Volt
phantom powering, but it is not a ”12-to-48
Volt” microphone. Any input to which it is
connected must implement one of those two
standard phantom powering methods. Not
only must the supply voltage meet the stan­dard; the resistors must be correct as well.

For applications in which it is certain that only
48-Volt or only 12-Volt phantom powering
will be used, the CMC 5 and CMC 3 (respec ­tively) remain available at slightly lower cost.
The CMC 6 offers greater flexibility in powering
as well as superior immunity to radio-frequency
interference; it is also the only amplifier model
which can be delivered in the special ”xt” ver­sion (see description under ”Special Versions”
below).

From an audio standpoint, the most signifi­cant difference between the CMC 6 and the
CMC 3 or 5 is the response at the very lowest
audio frequencies: The standard version of the

CMC 6 has a 12 dB/octave rolloff below 20 Hz
as a protection against infrasonics, while the
stan dard version of the CMC 3 or 5 has a 6 dB/
octave rolloff below 30 Hz. Any CMC amplifier
can be specially ordered, or modified after
delivery, for any desired rolloff frequency within
reason; please see the description of the CMC
”linear” version for further details.

In general if a 48-Volt microphone is con­nected to 12-Volt phantom powering, no dam­age will occur but the microphone will not work
properly. On the other hand a CMC 3 could
be powered safely and effectively by a 48-Volt
phantom supply if it can provide 11 mA per
microphone. But that current exceeds what is
required for standard 48-Volt phantom power­ing, and unfortunately many existing supplies
do not even meet the standard. Therefore this
mode of operation should not normally be
relied upon.

In the realm of film and video sound an
older system called ”parallel powering” or ”T”
powering (”Ton ader spei sung”) at 12 ± 1 Volts
is sometimes still used, particularly with Nagra
tape recorders; the CMC 4 amplifier model
works with that system. See Fig. 3, p. 6 for a
schematic diagram; since this method of pow­ering has been in decline for some time now,
it is not described in detail in this manual.
Please contact your SCHOEPS dealer or SCHOEPS
GmbH with any questions concerning its use.

Special Versions

CMC 6 U”xt” – the 40 kHz version

This variant is indicated by the letters ”xt”
engraved on the output socket. When an ”xt”
amplifier is used with any axially-addressed
Colette capsule, the response range of the
microphone will extend beyond 40 kHz. The
response above 10 kHz will also be elevated
slightly. Specific frequency response curves
can be seen in our main catalog or on our
Web site, www.schoeps.de .

CMC “+5 dB”

The sensitivity of a microphone with this ampli ­fier variant is 5 dB above the normal type,
while the equivalent noise level is somewhat

GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Types of Microphone Amplifiers

Microphone Amplifiers

4

greater. The increased output levels can help
to raise a microphone's signal above the input
noise level of the equipment to which it is
connected, especially when sound levels are
low to moderate. However, the overload limit
of that equipment, and of the microphone
itself, will also be reached 5 dB sooner.

CMC ”linear”

CMC microphone amplifiers normally have a
rolloff in response below 30 Hz (20 Hz in the
CMC 6) to guard against infrasonic distur­bances from various sources such as vibration
and air motion. However, when using pressure
(omnidirectional) transducers, particularly with
digital recording, it can be desirable to pick up
frequencies even lower than 20 - 30 Hz. The
special technology of the CMC microphone
amplifiers makes this possible; on request we
can deliver microphone amplifiers with response
extending as low as 3 Hz.

For live recording, however, some caution
is advised with respect to infrasonics. Since
pressure transducers can pick up very low fre­quencies, ventilation systems in large spaces
(churches, concert halls) or traffic rumble can
create a problem. With pressure gradient trans ­ducers the risk is even greater. They are far
less sensitive to very low frequency sound, but
respond much more strongly to low-frequency
mechanical stimuli such as air currents and
solid-borne noise. Such signals may be below
the audible range, but they can overload pre­amp inputs, particularly those that have
undersized input transformers.

Phantom Powering (DIN EN 61938)

(formerly DIN 45 596)

”Phantom” powering is a standard method of
providing the operating current for a micro­phone's circuitry through ordinary two-conduc­tor shielded cable. Precisely equal DC flows in
both modulation leads, making it ”invisible”
and harmless to most balanced microphones
that don't require such powering (e.g. most
dynamic microphones, including ribbons).
Exceptions are quite rare. The only likely cases
in which standard phantom powering will en -

danger a balanced microphone (e.g. a ribbon)
are if a microphone cable, con nector or adapter
is defective or wired in a non-standard way,
such that one modulation lead of the micro­phone is shorted to ground at DC while the
powering is on. If a microphone is connected
to such a cable with the powering turned on,
impulse current will flow through its coil or
ribbon, possibly causing damage.

Fig. 1 shows the only valid 48 V and 12 V
phan tom powering circuit (abbreviations: P48
and P12) that can be realized with resistors as
opposed to a center-tapped input transformer.
This illustration is based on the international
standard document EN 61938, ratified in

1997. Our microphones are developed and
tested with power supplies that con form to
the requirements of this standard. Proper oper­ation with non-standard power supplies can­not be guaranteed. Circuit arrangements that
deviate from the standard can cause opera­tional problems (i.e. distortion or even gaps in
the signal), particularly at high sound pressure
levels or in the presence of strong wind noise.
Such problems may often seem to defy analysis
until their real cause is discovered.

The permissible tolerance of the feed resistor
values as such is ±20%. However, the differ­ence between the resistors of any one pair
should be less than 0.4% (i.e. 27 Ohms for
48-Volt phantom powering with 6.8 kOhm).
This close matching is necessary to maintain
adequate common mode rejection. It will also
prevent significant DC from flowing through
the primary of the input transformer (if one is
present) and causing distortion or reduced
dynamic range.

A microphone designed for 48-Volt phan­tom powering could draw as much as 10 mA
according to the standard. A SCHOEPS CMC 5
or CMC 6 will draw about 4 mA even when
Active Accessories are used; this falls well
within the limit set by the prevailing standard.
There are certain commercially available power
supplies, preamplifiers, and mixing desks –
mostly older, but some more recent – which
fail to meet this standard and hence may not
be able to power SCHOEPS microphones ade­quately. Where doubt exists, equipment should

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Phantom Powering

Microphone Amplifiers

5

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Phantom Powering

Microphone Amplifiers

6

If possible, an unbalanced input should be bal­anced with a high-quality microphone input
transformer. That will also allow the signal leads
from the microphone to be balanced, for best
rejection of interference.

If such an arrangement is not possible, how­ever, a CMC microphone may be operated in
unbalanced mode by taking the signal from
pin 2 via a coupling condenser with a value as
shown in Figure 2 above. The signal from pin 3
must be left unconnected; do not short it to
ground. This ”unbalancing act” must occur
between the power supply and the preamplifier
input, however, since naturally all three pins
of the microphone must still connect to its
phantom or parallel power supply.

+ phase

- phase

2 (4)

3 (5)

microphone

1

screen

cable

powering

R

S

U

S

input

R

S

P48: US= 48 V ± 4 V; RS= 6,8 kW*, I

max.

= 10 mA

P12: U

S

= 12V ± 1V; RS= 680 W*, I

max.

= 15 mA

I/2

I/2

I

+ phase

- phase

2 (4)

3 (5)

microphone

1

screen

cable

powering

R

S

U

S

input

R

S

R

R

C

C

* see note in the text concerning tolerances

with XLR-5
(stereo microphones)

Fig. 2

To add phantom powering
to a balanced, grounded,
transformerless input, capa ­citors must be inserted into
the signal lines and polariza­tion resistors provided as
shown.

*

*

*

Fig. 1

Input with transformer
(or balanced, floating trans­formerless input)

XLR-3­connector

XLR-3
connector

XLR-3­connector

cable

Ohms

Ohms

* recommended values:

C: 100

μ

F, 63V; R: 22kΩ, 1%

** Tolerance ca. 5%; precise

matching is not critical.

Fig. 3

Parallel powering;
with parallel powering there is low-impedance
DC across pins 2 and 3. This can damage
dynamic microphones, especially ribbons.

z.B.
10 kOhm

**

**

R

*

be checked to verify its suitability for profes­sional work with SCHOEPS microphones. On
page 8 a method is described for checking a
phantom supply quickly and easily.

For P12 the standard allows a current of
15 mA. A SCHOEPS CMC 3 will draw 11 mA
while a CMC 6 needs 8 mA at 12 Volts.

Fig. 2 shows a bal an ced but groun ded am ­pli fier in put. In this case eit her a trans for mer
(see fig. 1) or ad di tio nal ca pa ci tors ha ve to be
in ser ted in the au dio li ne.

Unbalanced Operation

Unbalanced operation of CMC microphone
amplifiers is not recommended; both noise and
vulnerability to interference will be increased.

shield

shield

shield

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Technical Specifications, Electromagnetic Compatibility

Microphone Amplifiers

Amplifier type Powering Current Impedance Low-cut

consumption frequency (-3 dB)

CMC 6U / 6Uxt: 12 V phantom 8 mA 25 Ohms 20 Hz

48 V phantom 4 mA 35 Ohms 20 Hz

(automatic switchover)
CMC 5U: 48 V phantom 4 mA 35 Ohms 30 Hz
CMC 3U: 12 V phantom 11 mA 20 Ohms 30 Hz
CMC 4U: 12 V parallel 9 mA 13 Ohms 30 Hz

Polarity: Increasing sound pressure on the microphone's 0° axis produces a positive-going voltage

at pin 2.
Maximum output voltage: 1 V (at 1 kHz and 1 kOhm load resistance)
Minimum recommended load resistance: 600 Ohms (A load resistance below this value will par-

ticularly reduce the maximum output level.)
The other technical specifications depend on the choice of capsule – see page 12 ff.
Length: 116 mm (incl. 3 mm capsule thread)
Diameter: 20 mm
Weight: 65 – 68 g, depending on type
Surface finish: matte gray (g) or nickel (ni)

electromagnetic fields. This is particularly true
for CMC 6 amplifiers made since 2004; they
can be recognized by the gold-colored shield
plate in their output connector.

Due to the wide dynamic range of studio
microphones, the smallest signal amplitudes
are in the microvolt (1/1,000,000 Volt) range.
Cable shielding and the grounding scheme of
the preamp or mixer input are also crucial.
Thus no microphone can ever be immune to
all possible disturbances under all circumstances.
But the following suggestions can help to
reduce the likelihood of picking up noise:

1) Keep both the microphone and the cable

away from sources of interference such as

monitors, digital equipment (computers),

RF emitters (mobile phones), power trans-

formers, power lines, SCR dimmers, switch-

ing power supplies etc.

2) Use only high-quality cables with a high

degree of shield coverage.

3) Keep all cables as short as possible.

4) Dress audio cables away from power cables.

If they must cross, it should be at right angles.

5) At the preamp or mixer input, the shield of

the microphone cable should connect to

chassis ground in the shortest way possible.

If necessary, this coupling can be capacitive.

Simultaneous Connection to Multiple Inputs

If one microphone must be connected to mul­tiple inputs simultaneously, an active micro phone
splitter should be used in order to preserve
the loading and powering conditions for the
microphone, and to prevent interference.

Maximum Cable Length

Cable lengths of several hundred meters are
possible; Colette Series microphones are some ­times used with cables as long as 500 m (over
1/4 mile!). But the practical limit depends on
the electrical capacitance of the cable, which
is sometimes an unknown quantity. The lower
this capacitance is per unit length, the longer
the cable can be. All SCHOEPS cables have
very low capacitance (100 pF/m between the
conductors).

The main risks with excessively long micro­phone cables are losses at high frequencies
due to cable capacitance, reduced ability to
handle very high sound pressure levels, and
increased likelihood of picking up interference.

No tes on Electromagnetic Compatibility

SCHOEPS CMC microphone amplifiers are
virtually immune to magnetic, electric and

7

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Block Diagram of the CMC 3, 5, 6 Microphone Amplifiers

Microphone Amplifiers

8

Capsule

MK --

Capsule

MK --

Impedance

converter

Output

stage

DC/DC

converter

Regulator

EMI filter

e.g. cable KC -- or

tube RC --

Active Accessories:

3

1

4

2

3

1

3

1

3

1

4

2

3

1

Screen

-Phase

+Phase

XLR-3

Connector

2

3

1

2

3

1

2

Center contact ( )

Inner ring (0 V)

Middle ring (+60 V)

Outer ring (+6,2 V)

Microphone

cable

Microphone Amplifier

CMC --

Phantom

powering

U

s

= +48 V

R

s

= 6.8 kΩ

R

s

= 6.8 kΩ

∼

∼

Preampli -

fier,

recorder

or mixing

desk

4

1

2

3

*

*

**

∼

∼

3

1

Impedance

converter

+Phase: An excursion of the diaphragm towards the back electrode (posi-

tive pressure phase) leads to a positive signal at this pin.

*matched pair; see page 5

** Here are three simple methods for verifying correct phantom powering.

These measurements should be made at an unused input. Reduce the

channel gain to protect loudspeakers, etc. If microphones are connected

to other inputs at the same time, no substantial difference should occur

in the results.

1. Measure the open-circuit voltage between ground (pin 1) and either

pin 2 or pin 3 of the XLR input. Given the permitted tolerances, this

voltage should be between 44 and 52 VDC for P48, and between 11

and 13 VDC for P12. Then, measure the short-circuit current between

ground (pin 1) and either pin 2 or pin 3 of the XLR input. Given the per-

mitted tolerances, this current should be between 5.9 and 8.5 mA DC

for P48, and between 15 and 21 mA DC for P12.

screen

-phase

+phase

XLR-3

connector

XLR-3

connector

Pin 1: screen (GND)

Pin 2: +phase

Pin 3: –phase

Bottom view

(as the pins are seen)

1

2

3

Note: Well-designed phantom power supplies must tolerate at least a

temporary short circuit without damage; an unbalanced connection

(which is occasionally necessary) would cause the same current to be

drawn. To be safe, however, don't leave the short circuit in place longer

than necessary.

2) Measure the DC voltages on the modulation leads with a microphone

connected, e.g. by opening the connector shell of the cable. The two

voltages (from pin 2 and pin 3 to pin 1) must be identical. With a CMC 5

or CMC 6 and a 48-Volt supply, they should be about 34 Volts (mini-

mum = 30 Volts). For P12 this is 8.3 Volts (minimum 7.3 Volts) with a

CMC 3, and 9 Volts (minimum 8 Volts) with a CMC 6.

3) For P48, use a SCHOEPS PHS 48 tester. Plug it in to the XLR input socket;

if the LED glows and stays lit, all is well.

Nominal voltage gain: stan-

dard CMC amplifier: -2 dB,

”+5 dB” version: +3 dB.

MK -- Microphone Capsules

Which is the Best Capsule for ... ?

Only in rare cases can ”the” correct micro­phone be chosen unequivocally. The recording
location, the positions of sound sources and
the microphone, the atmosphere of the music
or other program material and the desired
effect must all be considered. Any absolute
prescriptions would thus be of limited value at
best. How ever, we would like to offer some
ideas to guide the choice that must be made.

Our Recommendations

The most commonly used pattern for medium­distance pickup is the cardioid (MK 4 or MK 4V).
However, there may be good reasons to make
a different choice. Some examples:

– Greater directivity may be required, either for

the sake of a ”drier” recording or to sup-

press sound from adjacent instruments. In

this case we recommend the supercardioid

MK 41 (as long as no nearby sound source

or P.A. loudspeaker is directly behind the

microphone's rear lobe).
– For a broader pickup pattern, with very nat-

ural sound quality for sound arriving at the

sides of the microphone and more extended

low-frequency response, we recommend

the MK 21 wide cardioid.
– For essentially perfect pickup of low-fre-

quency information and room sound, we

recommend the omnidirectional MK 2H or

MK 2S (for moderate miking distances).
– When using directional microphones with

very close placement, proximity effect must

be compensated with a bass rolloff. This is

especially true when miking instruments.

For voice, try the MK 4S or MK 4VXS. For

instruments the omnidirectional MK 2 may

be of interest (no proximity effect, low sen-

sitivity to ”popping” or solid-borne noise);

for grand piano, the BLM 03 C.
– For very distant miking and/or as an ”ambi-

ence” microphone, with essentially perfect

bass response: omni MK 3.

– For outdoor recording if directivity is not

required (e.g. close miking), the omni MK 2S
with windscreen W 5 or W 5 D will offer low
sensitivity to wind, ”popping” and handling
noise.
If high directivity is required outdoors, the
MK 41 can be used with the W 5 D, W 20 R1
or WSR MS ”basket”-type windscreens with
built-in elastic suspension for mono or stereo.

Attaching a Capsule or An Active
Accessory

MK -- capsules are interchangeable and can
be screwed onto any CMC -- amplifier or
Active Accessory (see System Overview, page 2).
To avoid damaging the threads, please proceed
as follows:

Place the capsule against the front end of

the microphone amplifier.

Now turn the capsule first counter-clockwise
(not pressing the parts together) until you feel
a gentle ”click”:

You are then at the beginning of the thread,
and can attach the capsule or accessory to the
microphone amplifier with normal clockwise
rotation:

(The engraved markings on the capsule may
not always line up as shown with those on the
amplifier.)

If you are using an Active Accessory, attach it
to the microphone amplifier in a similar man ner.

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Capsule Selection

Capsules

9

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Basic Characteristics of Transducers

Capsules

10

Essentially flat, with perfect reproduc­tion of low frequencies. The on-axis
response of the free-field capsule does
not have a high-frequency emphasis
but the capsule meant for the rever­berant sound field does.

Omnidirectional pattern in its ideal
form at low and middle frequencies.
At very high frequencies there is
increasing directivity. For this reason
even omnidirectional microphones are
aimed toward the sound source.

No proximity effect

Very little; simple foam-type wind­screens are usually sufficient.

Reduced sensitivity (rolloff) at lower
frequencies, which can be compen­sated by close placement to the
sound source (proximity effect)

Types: wide cardioid, Open Cardioid,
cardioid, supercardioid (hypercar­dioid), bidirectional (figure-8). The
frequency response of our figure-8 is
nearly the same in all directions; the
wide cardioid capsule has this advan­tage also.

Proximity effect: Elevation of the low
and low-mid frequencies as working
distance decreases (quite noticeable
at less than 50 cm)

Possibly considerable; shock mounts
and more elaborate windscreens
may be necessary.

Characteristics of the Two Basic Transducer Types

All the wide variety of SCHOEPS capsules, without exception, are single-diaphragm electrostatic trans­ducers. They fall into two general categories: pressure transducers and pressure gradient transducers.
Many of our capsules combine the two principles of operation in various proportions, yielding pat­terns from wide cardioid through supercardioid; these capsules are classed as pressure gradient
transducers by convention.

Unlike dual-membrane capsules, our switchable capsule offers flat low-frequency response, low
sensitivity to wind and solid-borne noise, and no proximity effect in its omnidirectional setting. In its
cardioid setting it maintains its directional pattern to the lowest frequencies, which dual-diaphragm
capsules do not do.

The following table lists the basic characteristics of these two general types.

SCHOEPS ”Colette” Series capsules (MK --) can be used interchangeably on all CMC-series amplifiers.
They can also be used with three special-purpose amplifier types: the CMBI (powered by internal bat­tery, with unbalanced output), the VST 62 IU (two-channel, balanced, phantom-powered) and the M 222
(modern, transformerless vacuum-tube circuitry). The operating requirements and range of accessories
for these amplifiers vary; for detailed information please see the main catalog or www.schoeps.de.

Pressure Transducers (omnis)

MK 2, 2H, 2S, 3,

BLM 3, BLM 03C

MK 5 in the ”omni” position

Pressure Gradient Transducers

MK 21, 21H, 22, 4, 4V, 41, 41V, 8

MK 5 in the ”cardioid” position,

MK 4S, 40, 4A, 4VXS, 41S

Frequency
response:

Directional
pattern:

Near field
behavior:

Sensitivity to
vibration, wind
and popping:

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Suggested Capsules for Specific Applications

Capsules

11

Applications: Recommendations:

On a lectern MK 4 (cardioid) with close-speech guard B 5 D
Conference recording MK 4 (cardioid) with close-speech guard B 5 D
TV speaker’s table MK 4 (cardioid), no popscreen required at distances greater than

0.5 m
Radio announcer MK 4V (cardioid with lateral pickup) with pop filter PR 120 SV
Noisy environments (super-)cardioid for close pickup (10 – 20 cm) with bass rolloff:

MK 4S, MK 40, MK 41S
TV “round table” discussion MK 4 (cardioid) or boundary layer capsule BLM 03 Cg (hemisphere)
Church MK 40 (cardioid) (perhaps as boundary layer microphone with BLC),

or BLM 03 C
Stage radio microphone type HXiR (AUDIO Ltd.) with MK 4 (cardioid) and

B 5 D popscreen or MK 2S (omni)
News reporting MK 5 (omni / cardioid, switchable) with windscreen B 5 D or W 5 D

or W 20 R1 (use the omni setting if there is strong wind)
Stage (movable) radio microphone HXiR (AUDIO Ltd.) with MK 4 (cardioid) or MK 2S

(omni) and popscreen B 5 D
Stage (fixed) MK 4 (cardioid) on RC Active Tube with windscreen B 5 D, vocalist

microphone CMH 64 (cardioid)
Studio MK 4, MK 4V (cardioids), MK 22 (Open Cardioid) with pop filter

PR 120 S, PR 120 SV
All instr. incl. percussion: MK 4 (cardioid); to pick up room sound as well:
especially for organ: MK 2S (omni); especially when the room’s character is less than opti-

mal or if the bass is too strong: MK 21 (wide cardioid) or MK 4

(cardioid)
Tympani, bass drum, etc. pressure transducers, e.g. MK 2
Instruments with adapters flute: MK 8 (figure-8), violin: MK 4V (cardioid), saxophone: MK 4

or MK 4V (cardioids)
Accent miking (spot mike) in the orchestra: MK 4 (cardioid), MK 41 (supercardioid), but also

MK 21 (wide cardioid) or MK 22 (Open Cardioid)
Orchestra, chorus ORTF microphone MSTC 64; for best low-frequency reproduction,

A/B recording e.g. with MK 2S or with BLM 3g or BLM 03 Cg;

Decca Tree with 3× MK 2S, perhaps using KA 50 accessory spheres
Small orchestra / ensemble M/S with RCY Active Tube, boundary layer microphone or modular

microphones, X/Y
Film and video dialog/effects M/S with MK 41 (supercardioid) in the M-channel or X/Y on a

boom, boundary layer with BLM 03 Cg e.g. under a thin table-

cloth or in a car under the top
Orchestra OCT surround; Decca Tree with 3× MK 2S, perhaps using KA 50

accessory spheres
Film and video dialog/effects Double M/S on a boom and possibly a Hamasaki Square for

increased envelopment

Surround

Stereo Instruments Vocals Speech / Speakers

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Pressure Transducers (Omnis)

Frequency response curve MK 2 + CMC 6

20 50 100 200 500 1k 2k 5k 10k 20kHz

Frequency response curve MK 2H + CMC 6

20 50 100 200 500 1k 2k 5k 10k 20kHz

Actual miking distances will depend
greatly on characteristics of the
recording environment – especially
size and reverberance – and on per­sonal preference.
Each of these capsules, when used
at appropriate distance, will have a
well-balanced overall response given
the mixture of direct and reflected
sound energy typical of that distance.

Note: Since the capsules have some
directionality at high frequencies, it
is still necessary to aim them with
respect to the sound source, even
though they are ”omnidirectional.”
With the microphone amplifier
CMC 6xt, the frequency range of
these capsules can be extended to
40 kHz.

+10

0dB

-10

-20

+10

0dB

-10

-20

*reverberation radius: the ”critical distance” from the sound source at
which the levels of direct and diffuse sound are equal in a given space.

Frequency response curve MK 2S + CMC 6

20 50 100 200 500 1k 2k 5k 10k 20kHz

Frequency response curve MK 3 + CMC 6

20

50

100 200 500

1k 2k 5k

10k

20kHz

+10

0dB

-10

-20

+10

0dB

-10

-20

MK 2 for free-field placement

(close to the sound source)

MK 2H for use at moderate dis-

tance (at or near the
reverberation radius*)

MK 2S all-purpose capsule for

music and speech, also
for use at moderate dis­tance (at or near the
reverberation radius*)

MK 3 for diffuse-field placement

(distinctly beyond the
reverberation radius*)

MK 3

MK 2S

MK 2 MK 2H

Polar diagram MK 2, -2H, -2S, -3

from outer
to inner:

up to 1 kHz 4 kHz

2 kHz 8 kHz

16 kHz

Capsules

12

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Boundary Layer Microphones

Capsules

13

Frequency response curve BLM 3g, BLM 03Cg + CMC 6

Polar diagram BLM 3g, BLM 03Cg

from outer

to inner:

up to 2 kHz 4 kHz

8 kHz

16 kHz

20 50 100 200 500 1k 2k 5k 10k 20kHz

+10

0dB

-10

-20

– boundary layer capsules
– hemispheric directional pattern
– no coloration of off-axis sound

Suggested applications:
Music (orchestra, including pit orches­tra); on-stage; speech.
BLM 03C: Round-table discussions

Note:
The BLM capsules rely on the bound­ary layer (”pressure zone”) effect.
They will have the frequency response
shown here only when placed on a
floor or another large, flat, rigid surface
which is not covered by thick carpeting
or other sound-absorbent material. For
speech applications such as conference
recording, a table top may suffice.

BLM 3g

BLM 03Cg

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Wide Cardioids / Open Cardioid

Capsules

14

Frequency response curve MK 21 + CMC 6

Polar diagram MK 21, -21H

from outer

to inner:

up to 1 kHz 4 kHz

2 kHz 8 kHz

16 kHz

+10

0dB

-10

-20

20 50 100 200 500 1k 2k 5k 10k 20kHz

Frequency response curve MK 21H + CMC 6

+10

0dB

-10

-20

20 50 100 200 500 1k

2k 5k

10k

20kHz

– wide cardioids
– polar pattern very well maintained

throughout the frequency range

– a favorable compromise between

omni (good low-frequency response)
and cardioid (consistent directional
pattern at all frequencies)

Suggested applications:
MK 21: music (orchestras), spot micro-

phone; vocals; speech

MK 21H: wherever a high-frequency

elevation is desired, esp. non-classi­cal music

MK 21

MK 21H

MK 22

– new kind of directional pattern:

”Open Cadioid”

– optimal combination of classic car-

dioid directionality (MK 4) with the
sonic character of the wide cardioid
(MK 21)

– directional pattern largely constant

throughout the frequency range

Suggested applications:
as spot / soloist’s microphone

20 50 100 200

500

1k 2k 5k 10k 20kHz

Frequency response curve MK 22 + CMC 6

Polar diagram MK 22

von außen

nach innen:

bis 2kHz 4kHz

8kHz

16kHz

+10

0dB

-10

-20

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Cardioids

Frequency response curve MK 4V + CMC 6

Polar diagram MK 4V

from outer

to inner:

up to 2 kHz 4 kHz

8 kHz

16 kHz

+10

0dB

-10

-20

20 50 100 200 500 1k 2k

5k

10k 20kHz

MK 4

– standard cardioid with clear sound

quality, free of coloration

– all-purpose capsule for music and

speech

– our best-selling capsule type

– 0° axis is at the tip of the capsule

MK 4V

– cardioid with mild high-frequency

boost

– all-purpose capsule for music and

speech
– highly consistent polar response
– 0° axis is at the side of the capsule

marked by a red dot

Note:
Though not specifically designed for such use, the MK 4V capsule can also be
used on the RC Active Tube or the variable angle joint GVC; when fully
tightened it will rarely be aimed where you intend. On request we will supply
an elastic ring which can be slipped over the threads of the RC or GVC so
that the final turn of the capsule will place it at the desired angle of rotation.
This ring must be kept out of the capsule threads, however.

Capsules

15

Frequency response curve MK 4 + CMC 6

Polar diagram MK 4

from outer

to inner:

up to 1 kHz 4 kHz

2 kHz 8 kHz

16 kHz

20 50 100 200 500 1k 2k 5k 10k 20kHz

+10

0dB

-10

-20

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Supercardioids

Frequency response curve MK 41V + CMC 6

Polar diagram MK 41V

from outer

to inner:

up to 2 kHz 4 kHz

8 kHz

16 kHz

+10

0dB

-10

-20
20 50 100 200 500 1k

2k 5k 10k 20kHz

MK 41

– all-purpose capsule for speech and

music recording of all kinds

– well suited for use as the main

microphones for stereo pickup
and/or as ”spot” microphones

– extended, smooth, well-balanced

frequency response
– often used for film and video sound
– has distinct sonic and practical

advantages over most shotgun

microphones
– highly consistent polar response
– 0° axis is at the tip of the capsule

Note:
Though not specifically designed for such use, the MK 41V capsule can also be
used on the RC Active Tube or the variable angle joint GVC; when fully
tightened it will rarely be aimed where you intend. On request we will supply
an elastic ring which can be slipped over the threads of the RC or GVC so
that the final turn of the capsule will place it at the desired angle of rotation.
This ring must be kept out of the capsule threads, however.

Capsules

16

MK 41V

– all-purpose capsule for music and

speech; same uses and advantages

as the MK 41
– 0° axis is at the side of the capsule

marked by a red dot

Frequency response curve MK 41 + CMC 6

Polar diagram MK 41

from outer

to inner:

up to 1 kHz 4 kHz

2 kHz 8 kHz

16 kHz

+10

0dB

-10

-20
20 50

100

200 500 1k

2k 5k

10k

20kHz

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Figure-8 / Switchable Capsule

Frequency response curve MK 8 + CMC 6

Polar diagram MK 8

from outer

to inner:

up to 2 kHz 4 kHz

8 kHz

16 kHz

+10

0dB

-10

-20

20 50 100 200 500 1k 2k 5k 10k 20kHz

MK 5

– mechanically switchable single-dia -

phragm capsule (omni / cardioid)

– smoother, more extended high-fre-

quency response than most other
multi-pattern microphones (e.g.
dual-diaphragm capsules of other
manufacturers)

– a pure pressure transducer when in

the ”omni” setting (flat, extended
low-frequency response without
proximity effect or undue sensitivity
to wind or solid-borne sound)

– slightly brighter than the MK 2H

(omni) or MK 4 (cardioid)

Intermediate switch positions are
mechanically possible, but are not
reproducable or recommended.

Capsules

17

Frequency response MK 5 ”omni” + CMC 6
Polar diagram identical to that of MK 2, -2H, -2S, -3

+10

0dB

-10

-20

20 50 100 200 500 1k 2k 5k 10k 20kHz

Frequency response MK 5 ”cardioid” + CMC 6

Polar diagram MK 5

from outer

to inner:

up to 2 kHz 4 kHz

8 kHz

16 kHz

+10

0dB

-10

-20

20

50 100 200 500 1k 2k 5k 10k 20kHz

”cardioid” position

MK 8

– figure-8 (”bidirectional”) pattern
– clear sound quality, free of coloration
– for M/S and Blumlein stereo
– highly consistent frequency and

polar response

– response essentially free of off-axis

peaks like a good ribbon microphone
(but not as delicate physically)

– lateral pickup

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Cardioids for Close Pickup

Frequency response curve MK 4S + CMC 6
Polar diagram identical to that of the MK 4

+10

0dB

-10

-20

20 50 100 200 500 1k 2k 5k 10k 20kHz

When a directional microphone is
used close to a sound source, its low­frequency response increases greatly.
This ”proximity effect” gives voices an
artificial ”boomy” quality which is
sometimes useful as a special effect,
but it reduces intelligibility and causes
listener fatigue.

To avoid this problem and to reduce
the effects of breath noise and pop­ping on consonants, low-frequency
filtering can be applied (e.g. the CUT 1
Active Filter) or special speech capsules
with reduced low-frequency sensitivity
can be used. These same measures
also help to suppress low-frequency
environmental noise.

MK 4S

– for close pickup (ca. 50 cm = 20")

MK 40

– for close pickup (ca. 50 cm = 20")
– high-frequency emphasis for better

speech intelligibility in reveberant
venues (e.g. churches)

MK 4VXS

– for extremely close pickup (under

10 cm = less than 4")

– lateral pickup

MK 40MK 4S

Capsules

18

MK 4VXS

Frequency response curve MK 40 + CMC 6

Polar diagram MK 40

from outer

to inner:

up to 2 kHz 4 kHz

8 kHz

16 kHz

+10

0dB

-10

-20

20 50 100 200 500 1k 2k 5k 10k 20kHz

20 50 100 200 500 1k

+10

0dB

-10

-20

MK 4 standard

cardioid

MK 4S and MK 40

MK 4A

MK 4VXS

Frequency response curve MK 4VXS + CMC 6
Polar diagram essentially identical to that of the MK 4V

+10

0dB

-10

-20

20 50 100 200 500

1k

2k

5k

10k 20kHz

The frequency response curves shown on these pages were ob tained
at the usual one-meter equivalent measuring distance. They show
low-frequency rolloffs which will suppress low-frequency en viron ­mental noise. When these capsules are used at the indicated working
distances, proximity effect and the low-frequency rolloff will bal­ance each other out, creating a natural-sounding pickup of the voice.

Low-frequency
attenuation of
cardioids for
close pickup

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Cardioids / Supercardioid for Close Pickup

Frequency response curve MK 41S + CMC 6

Polar diagram MK 41S

from outer

to inner:

up to 2 kHz 4 kHz

8 kHz

16 kHz

+10

0dB

-10

-20

20 50 100 200 500 1k 2k 5k 10k 20kHz

MK 41S

– supercardioid for close pickup

(under 50 cm)

– considerable low-frequency

attenuation
– compensates for proximity effect
– suggested application: speech in a

loud environment

Capsules

19

MK 4A

– for extremely close pickup (under

10 cm = less than 4")
– deliberate 10 dB reduction in

sensitivity
– especially well suited for hand-held

radio microphones made by AUDIO

Ltd. (England)

Polar diagram MK 40

from outer

to inner:

up to 1 kHz 4 kHz

2 kHz 8 kHz

16 kHz

Frequency response curve MK 4A + CMC 6

+10

0dB

-10

-20

20 50 100 200 500 1k 2k 5k 10k 20kHz

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Specifications

Capsules

20

Capsule Type Polar Frequency Range Sensitivity Equivalent Noise Level Signal-to-Noise Max. SPL

Pattern CCIR A-weighted Ratio (0.5% THD)

A-weighted

MK 2 omni 20 Hz – 20 kHz* 15 mV/Pa 23 dB 11 dB 83 dB 130 dB

MK 2H omni 20 Hz – 20 kHz* 15 mV/Pa 23 dB 12 dB 82 dB 130 dB

MK 2S omni 20 Hz – 20 kHz* 12 mV/Pa 24 dB 12 dB 82 dB 132 dB

MK 3 omni 20 Hz – 20 kHz* 10 mV/Pa 26 dB 14 dB 80 dB 134 dB

BLM 3g hemisphere 20 Hz – 20 kHz 19 mV/Pa 23 dB 12 dB 82 dB 128 dB

BLM 03 Cg hemisphere 20 Hz – 20 kHz 19 mV/Pa 23 dB 12 dB 82 dB 128 dB

MK 21 wide cardioid 30 Hz – 20 kHz* 13 mV/Pa 25 dB 15 dB 79 dB 132 dB

MK 21H wide cardioid 30 Hz – 20 kHz* 10 mV/Pa 26 dB 16 dB 78 dB 134 dB

MK 22 Open Cardioid 40 Hz – 20 kHz* 14mV/Pa 23 dB 14 dB 80 dB 131 dB

MK 4 cardioid 40 Hz – 20 kHz* 13 mV/Pa 24 dB 15 dB 79 dB 132 dB

MK 4V cardioid 40 Hz – 20 kHz 13 mV/Pa 24 dB 14 dB 80 dB 132 dB

MK 41 supercardioid 40 Hz – 20 kHz* 13 mV/Pa 24 dB 16 dB 78 dB 132 dB

MK 41V supercardioid 40 Hz – 20 kHz 13 mV/Pa 24 dB 15 dB 79 dB 132 dB

MK 8 figure-8 40 Hz – 16 kHz 10 mV/Pa 26 dB 18 dB 76 dB 134 dB

MK 5 omni 20 Hz – 20 kHz* 11 mV/Pa 26 dB 14 dB 80 dB 133 dB

cardioid 40 Hz – 20 kHz 13 mV/Pa 25 dB 16 dB 78 dB 132 dB

MK 4S cardioid 80 Hz – 20 kHz 13 mV/Pa 24 dB 15 dB 79 dB 132 dB

MK 40 cardioid 80 Hz – 20 kHz 18 mV/Pa 22 dB 13 dB 81 dB 129 dB

MK 4A cardioid close pickup 3 mV/Pa 29 dB 18 dB 76 dB 144 dB

MK 4VXS cardioid close pickup 10 mV/Pa 24 dB 14 dB 80 dB 134 dB

MK 41S supercardioid 80 Hz – 20 kHz 13 mV/Pa 24 dB 15 dB 79 dB 132 dB

Specifications for Complete Microphones: MK -- Capsules with CMC 6 Microphone Amplifier

* When the CMC 6 xt microphone amplifier is used with axially addressed capsules, the frequency response extends

beyond 40 kHz.

A word about signal-to-noise specifications for studio micro­phones: The standard method, which we follow, is really just
an alternate way of stating a microphone's equivalent noise
level. It is designed to allow comparison of noise floor levels
for different microphones. Unlike the signal-to-noise specifica­tions for other types of audio equipment, which give the ratio
of a component's clipping point to its noise floor, these values
do not indicate a microphone's entire available dynamic range.
Instead, the values are measured with reference to a standard
sound pressure level of 1 Pascal (1 Pa = 94 dB SPL). But the
actual maximum SPL capability of any usable microphone

exceeds that reference level substantially. The signal-to-noise
specifications of our microphones would be 35 to 40 dB (!)
greater if the ”hi-fi” approach were used.

The use of ”A” weighting when specifying the equivalent
noise level of microphones is another often-misunderstood
aspect of the standards. ”A” weighting yields a distinctly
lower noise specification – often by 10 dB or thereabouts –
and this figure, of course, becomes the one most often cited
in advertising. But the CCIR weighted noise level may well be
a more accurate indicator of a microphone's perceived noise
level in practice.

Care of Colette Series Condenser
Microphone Capsules

Please be careful to avoid placing capsules in
a dusty environment. Keep them in their cases
(or in the wood case of the microphone ampli­fier) when not in use, since any dust that gets
inside the capsules can adversely affect their
functioning. In combination with humidity it
can lead to condensation and thus popping
and crackling noises (often described as ”frying
sounds”).

What to do if …
the microphone is noisy (clicks and pops) in high
humidity?

– If the microphone is brought from the cold

outdoors into a warm environment, snapping
or clicking noises can result from the con­densation of moisture. In such a case the
microphone should be given time to reach
room temperature, and as a rule it will then
perform flawlessly.

– Sometimes dirt can get into the contacts at

the end of the microphone amplifier or of
an Active Accessory where the capsule is
attached; this, too, can cause impulse noise.
You can clean the contacts yourself by using
compressed air (without lubricant) from an
aerosol can. If that doesn't help, you can
scrub them with a new, clean toothbrush
dipped in isopropyl alcohol, holding the
microphone amplifier or Active Accessory
so that the contacts face downward. Shake
off any extra fluid; under no circumstances
can it be allowed to flow into the amplifier!
Be careful to wipe the contacts dry.

If this treatment does not eliminate the noise,
it is possible that dirt has gotten inside the
capsule itself – in which case the capsule must
be sent back to the factory for cleaning. We
strongly urge customers not to open a cap­sule or attempt to clean it themselves. Doing
so would also void all warrantees. Neither
should the contact rings of a capsule be
cleaned with any kind of liquid. Windscreens
are recommended when micro phones have to

be used in dirty or dusty environments in order
to avoid problems of the kind described above.

Possible Problems

Wind Noise and Polar Pattern

Noise problems may be a consideration when
choosing a microphone pattern (directional
characteristic) for a given set of recording con­ditions. Pressure transducers are considerably
less prone than pressure gradient transducers
(such as cardioids or supercardioids) to pick
up noise from air currents or mechanical
vibra tion. SCHOEPS omnidirectional capsules
are pressure transducers, as are our switchable­pattern capsules in their omnidirectional set­tings. If strong wind is anticipated, or physical
vibration of the microphone, perhaps a pressure
transducer such as the MK 2 S should be used
instead of a cardioid or supercardioid. The dis­tance between the microphone and the sound
source should then be reduced by about half
if possible.

Wind Noise and Windscreens

Air motion (wind, vocal ”popping” on sung
or spoken consonants, motion of the micro­phone on a boom arm, or air currents due to
heating or air conditioning systems) can cause
noise that should always be dealt with. Even if
it doesn't cause overload, it will detract from
the clarity of sound. A wind or pop screen
should be used, but should be chosen carefully
to avoid changing the microphone's character­istics too much. Many screen types which are
effective at reducing wind noise also have a
tendency to reduce a microphone's direction­ality and/or its high-frequency response. Basket­type windscreens are generally more effective
than foam-type windscreens when directional
capsules are being used, and their main side
effect is to create some unevenness in frequency
response (see our main catalog for details).

Vibration

If noise from mechanical vibration enters a
stand- or boom-mounted microphone, a shock
mount (elastic suspension) should be used, and

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Care and Maintenance / Possible Problems

Capsules

21

a loop of slack cable should be isolated and
tied off so that it does not become another
way for vibrations to reach the microphone.
Unlike a wind screen, a shock mount will not
affect the characteristics of a microphone. In
many kinds of work it is well justified to use a
shock mount ”by default.”

Overload

When dealing with problems of overload, it is
useful to think of your recording equipment
as a series of circuit stages. The goal is to find
the first stage that is being overloaded, and to
attenuate the signal at the input to that stage.
Reducing the gain at any earlier stage would
add unnecessary noise, while reducing it at a
later stage would not solve the problem.

A condenser microphone represents two cir­cuit stages: the capsule and the amplifier. In
practice, capsules are rarely overloaded except
by explosions or very strong wind; the only
sound pressure levels that could overload a
SCHOEPS capsule are so extreme – ca. 150 dB
SPL – that they would quickly damage human
hearing. Properly powered SCHOEPS CMC
amplifiers can normally handle 130+ dB sound
pressure levels, depending on the capsule type.
Such levels rarely occur in unamplified sound,
though their equivalents can be caused by wind
when directional capsules are used. In addition,
proper powering should not be taken for
granted; insufficient or incorrect microphone
powering has proved to be the cause of many
otherwise mysterious “overload” problems.

If wind and powering can be excluded as
possible issues, however, overload is far more
likely to occur in the input circuitry of mixers,
preamps or recorders than in SCHOEPS CMC-
series microphones. This is true particularly
with consumer audio equipment, though even
today some professional equipment is still
designed primarily for use with dynamic micro ­phones or with earlier, less sensitive condenser
microphones. If an input sensitivity control is
available, it should be set low enough to avoid
input overload, but not so low as to cause
excess noise – though a few dB of extra hiss is
preferable to the risk of hard clipping. Level
meters and overload indicators don’t generally

detect input overload even in fully professional
equipment; they operate only at later stages
of the circuitry.

If overload occurs where powering, high
sound pressure levels and wind are not the
problem and an input sensitivity control can­not be turned down, the next logical step is
to plug in a balanced resistive ”pad” (attenu­ator) such as the SCHOEPS MDZ 10 or MDZ 20
at the preamp input. If the sound quality
improves, leave the pad in place; as long as a
microphone isn’t being overloaded, it is always
better to pad the preamp input than the micro­phone. Only if there are extreme sound pres­sure levels should a capacitive attenuator
(SCHOEPS DZC 10 or DZC 20) be used.

Low-frequency disturbances such as wind
and solid-borne vibration may not be directly
audible as such, but infrasonic noise can still
cause overload in some stage of the signal
chain. A windscreen then becomes the first
line of defense. But low-frequency noise can
also be effectively suppressed in SCHOEPS
Colette microphones with the Active Filters
CUT 1 or CUT 2, inserted between the capsule
and amplifier. These filters have the side effect
of raising a CMC amplifier’s gain to that of the
+5 dB option (see pages 4 and 5), but given
the enormous levels of noise which can be
generated by wind, they are helpful far more
often than not. Alternatively, the simpler low­cut filters LC 60 or LC 120 can be placed at
the input of a phantom-powered preamp.

Overload which does not otherwise seem
to make sense may actually be a symptom of
incorrect or inadequate microphone powering.
Powering systems and their requirements are
discussed near the beginning of this manual
on page 5.

The least expensive, most helpful trouble ­shooting tools are:
– a known good microphone cable
– a simple pop screen such as the SCHOEPS

B 5 (or for outdoor recording, a wind

screen such as the SCHOEPS W 5)
– a balanced, in-line resistive attenuator (”pad”)

such as the SCHOEPS MDZ 10 or MDZ 20
– an ordinary multimeter or the SCHOEPS

PHS 48 phantom power tester

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Possible Problems

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Warranty

We guarantee our products for a period of
twenty-four months, except for batteries.
The guarantee period begins on the date of
purchase.

Please provide your bill of sale in all cases as
proof of guarantee; without it, repairs will be
undertaken only at the owner's expense.
We reserve the right to satisfy all warranty
requirements regarding defects of workman­ship or materials by means of repair or partial
or complete replacement of the product, at
our sole discretion.

Excluded from this guarantee are defects due
to misuse (e.g. incorrect operation; mechanical
damage), abuse or “Acts of God.” This guar­antee is nullified in the event of tampering by
unauthorized persons or agencies.

To secure your rights under this guarantee,
send the product with proof of purchase and
a precise description of the malfunction, at your
expense, either to SCHOEPS (if you are a cus­tomer in Germany), or to our representative
(if you are a customer outside of Germany).

Prior to sending your defective product for
repair, please contact your local dealer or dis­tributor for instructions. In exceptional cases
you can, by prior arrangement with SCHOEPS,
send the product directly to us from a foreign
country. However any return shipment must
then be prepaid; this tends to cause delays,
especially for non-warranty service. Full pay­ment must be made before a repaired item
can be returned to the customer.

This guarantee does not affect any contractual
agreements which may exist between the buyer
and seller of the equipment.

This guarantee is world-wide.

Declaration of Conformity – CE-Mark

The CE-mark guarantees that all products
conform to relevant standards approved by
the European Community. The products
described in this User Guide comply with cur­rent, relevant standards when used with cables
from SCHOEPS.

Relevant directives:
EMC Directive: 89/336/EEC, amended by

92/31/EEC and 93/68/EEC

Relevant standards:
EN 55 103-1, -2 and those which are referred

to by them.

SCHOEPS GmbH · Spitalstr. 20 · D-76227 Karlsruhe (Durlach) · Tel: [phone] · Fax: [phone]

www.schoeps.de · [email protected]

Warranty / Declaration of Conformity

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Subject to change without notice.
Not responsible for errors or omissions.

091102

Technik

Schall

SCHOEPS GmbH
Spitalstrasse 20
D-76227 Karlsruhe (Durlach)
Germany

Tel: [phone]
Fax: [phone]

www.schoeps.de
[email protected]